I recently bought this truck and the tranny shifts great and the truck runs fine. I only have one prob. When running down the interstate at 74-76 mph the truck feels as if the tranny bumps or something. This only happens every 20+ miles. It is very hard to explain. But when I slow down the trans downshifts well and upshifts well. Could it be a trans solenoid? This only happens at this constant speed. Has anyone seen anything like this before? Let me know if you have any ideas on where to trouble this. Thanks for any help